Improvement in cement sewer-bottoms



UNITED STATES PATENT OFFICE IWIARCELLUS DAY, OF CHARLESTOWN, MASSACHUSETTS.

IMPROVEMENT IN CEMENT SEWER-BOTTOMS.

Specification formingpart of Letters Patent No. 144,961, dated Novembcr 25,1873; application filed October 2, 1873.

for the bottom of the masonry-work of brick or stone sewers, and to carry oft' the water at the bottom of the trench while the process of constructing1 the sewer is progressing.

For such manufacture I use a straight mold or a mold of uniform size in cross-section throughout its length, and containing one or more straight cores, (extending through the mold from end to end, and parallel to its sides.) The space between said core or cores and the inner surface formed by the mold-plates, is lled with a mortar, preferably composed of hydraulic cement, sand or gravel, and Water, the mortar being put into the mold little by little and tamped. The cores and shell are then removed, and the sewer-bottom formed between them is finished or hardened by drymg.

My invention consists in the sewer-bottom thus formed.

The drawing represents the sewer-bottom and mold. v

Figure l shows the mold-core and production in end view. Fig. 2 is a side view of the mold. Fig. 3 shows the sewer-bottom separate from the mold.

a and b denote two cast-iron plates which form the outer shell of the mold, said plates being strengthened by ribs c, and having anges d, which abut together at the opposite sides of the mold, and are connected by clamps e. The plate a is fiat or approximately flat,

l except at its opposite side edges, to form a correspondinglyshaped face for the bottom surface ofthe blank, and the other plate, b, is made with a center curve to form the top face of the blank, (such face making the bottomsurface of the sewer,) and arin g straight sides fand shoulders g, from which the brick-arch springs. l1. h denote the two straight cores, preferably made as cast-iron tubes, shaped substantially as shown, or so as to form between them and the plates such a space that the blank or article molded between them will be of about the same thickness throughout.

In molding the mortar the plates and cores plate, i, recessed to receive and sustain them, and then the mortar, mixed and worked to the proper consistency, is poured or dropped into the molding-space, and is driven in by tamping until the mold. is Iilled. After standing a suitable time, the plates are removed and the cores drawn, the sewer-bottom k, thus formed between them, being completed by setting or drying.

The cores may extend at bottom through the bed-plate i and into pits beneath, so that they can be removed by pressing them down into the pits, such movem ent insuring a smooth linish to the upper end of the sewer-bottom.

The tubular structure thus formed makes a perfect foundation for the arch or brick-Work of the sewer, and furnishes an adequate escape for accumulating water, as before described, and its cheapness and effectiveness lead to its extensive use.

The mold is not herein claimed, as it is to form the subject of a future application.

I claim- The tubular sewer-bottom or section, formed to shape in a mold, of the material and by the process substantially as described.

l MARCELLUS DAY. Witnesses FEANcIs GoULD, M. W. FROTHINGHAM.

are placed in standing posit-ion upon a bedv 

